/Engine/Plugins/Online/OnlineSubsystem/Source/Public/Interfaces/OnlinePartyInterface.h
enum ELeavePartyCompletionResult { UnknownClientFailure = -100, NoResponse, LoggedOut, UnknownParty, LeavePending, UnknownLocalUser, NotMember, MessagingFailure, UnknownTransportFailure, UnknownInternalFailure = 0, Succeeded = 1, }